THE IMPORTANCE OF WATER

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2 THE IMPORTANCE OF WATER 2/3rds of the Earth s surface is covered in. water Earth s aquatic ecosystems contain biomass more (living mass) than its terrestrial ecosystems. Phytoplankton are microscopic producers which are found in huge numbers in the oceans. They make more than % 50 of the Earth s oxygen gas and form the foundation of marine food webs and ecosystems.

3 THE IMPORTANCE OF WATER % 97 is salt water % 3 is fresh water (Most is frozen so it is unusable unless it.) melts % <1 of fresh water is easily available for use as ground water and surface water.

4 THE IMPORTANCE OF WATER % 66 % 80 % 95 human potato tomato The majority of living things are made up mostly of water. The water is necessary to help organisms transport substances within themselves and between themselves and the outside environment.

5 sun clouds water vapor plants glacier, iceberg sea, ocean land aquifer lake, river

6 Water vapor is water in its gas state. In this state, water can travel through the atmosphere.

7 sun clouds water vapor plants glacier, iceberg sea, ocean land aquifer lake, river

8 A glacier is a large persistent body of ice on land that forms when the forces that erode it (like melting) do not exceed the forces that create it (like precipitation) over a long period of time (e.g. centuries). Moreno Glacier in Argentina

9 However, many of our glaciers and icecaps have undergone a drastic reduction over the last few decades due to. climate change We will examine the effects of this later. Muir Glacier in Alaska

10 An iceberg is a large piece of freely floating ice. Often they break off from the main part of a glacier when the glacier melts and cracks.

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12 When it gets colder the water between the icebergs freeze creating. land bridges

13 sun clouds water vapor plants glacier, iceberg sea, ocean land aquifer lake, river

14 An aquifer is a large underground reservoir (storage area) for fresh water.

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16 sun clouds water vapor plants glacier, iceberg evaporation sea, ocean land aquifer lake, river

17 Evaporation occurs when water goes from a liquid to a gas state to form water. vapor

18 sun clouds water vapor plants glacier, iceberg evaporation melting sea, ocean freezing land aquifer lake, river

19 Freezing converts water from the liquid state to the solid state. Melting converts water from the solid state to the liquid state.

20 sun clouds water vapor plants glacier, iceberg evaporation melting sea, ocean freezing land aquifer lake, river

21 Sublimation converts water from the solid state to the gas state.

22 Deposition converts water from the gas state to the solid state. Sublimation converts water from the solid state to the gas state.

23 sun condensation clouds water vapor plants glacier, iceberg evaporation melting sea, ocean freezing land aquifer lake, river

24 Condensation converts water in its gas state (water vapor) into its liquid state. This usually occurs when the vapor is in contact with cold air (or a cold surface) causing the vapor to gather into visible liquid droplets.

25 sun condensation clouds water vapor plants glacier, iceberg evaporation melting sea, ocean freezing land aquifer lake, river

26 Transpiration is the release of water vapor from the surface of plants.

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28 sun condensation water vapor clouds precipitation plants glacier, iceberg evaporation melting sea, ocean freezing land aquifer lake, river

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30 Precipitation occurs when small water droplets in a cloud gather together to form rain, snow, sleet or hail which is heavy enough to fall to the Earth.

31 sun condensation water vapor clouds precipitation plants glacier, iceberg evaporation melting sea, ocean freezing percolation land aquifer lake, river

32 Hot water is pulled through the coffee grinds due to gravity. Percolation in the water cycle occurs when water is being pulled downwards by gravity through the layers of. soil

33 sun condensation water vapor clouds precipitation plants glacier, iceberg evaporation melting sea, ocean freezing percolation land aquifer run-off lake, river

34 Run-off occurs when excess rain water or melt water cannot be absorbed by the soil, and so it overflows on the surface or drains into waterways.

35 sun condensation water vapor clouds precipitation plants glacier, iceberg evaporation melting sea, ocean freezing percolation land aquifer run-off lake, river

36 HUMAN IMPACT ON THE CYCLE Water and the water cycle is of vital importance to all living things on the Earth. Certain human activities threaten to disrupt this cycle which has drastic consequences for our ecosystems and ourselves. Let us examine the effects of the following on the water cycle: 1) 2) 3) Global Warming Deforestation Climate Change Thank goodness for all this water!

37 HUMAN IMPACT ON THE CYCLE GLOBAL WARMING is the increase of the Earth s temperature due to the trapping of heat in the atmosphere by greenhouse gases released by human activities. This has several effects: 1) It Melts Glaciers and Icecaps Arctic Icecap With less ice and snow, this creates more dark areas on the surface of the planet. Darkly colored materials, like ocean water and land, absorb heat and lighter colored materials like, ice and snow, reflect heat. More melting then feeds back into the cycle to create more global warming.

38 HUMAN IMPACT ON THE CYCLE GLOBAL WARMING is the increase of the Earth s temperature due to the trapping of heat in the atmosphere by greenhouse gases released by human activities. This has several effects: 1) It Melts Glaciers and Icecaps There are other effects as well Arctic Icecap

39 HUMAN IMPACT ON THE CYCLE GLOBAL WARMING is the increase of the Earth s temperature due to the trapping of heat in the atmosphere by greenhouse gases released by human activities. This has several effects: 2) It Effects the Thermohaline Circulation of the Oceans This is a major part of what causes ocean currents (massive movements of water) to occur. The THC is driven by the density of the sea water which is influenced by both the temperature and the salt content of the water.

40 HUMAN IMPACT ON THE CYCLE GLOBAL WARMING is the increase of the Earth s temperature due to the trapping of heat in the atmosphere by greenhouse gases released by human activities. This has several effects: 2) It Effects the Thermohaline Circulation (THC) of the Oceans As more fresh water is added to the oceans due to the melting ice caps, this affects the salt content, and hence the density, of the ocean water. Without the correct density, the ocean water will not be able to circulate properly, affecting all life on the planet.

41 HUMAN IMPACT ON THE CYCLE DEFORESTATION is the removal of a large number of trees from an area. 1) In drier climates this can lead to desertification. Without, plant roots less water is held in the topsoil and it becomes dry and blows. away Without trees transpiration decreases, which decreases the amount of water vapor, decreasing cloud formation causing less. precipitation 2) In wetter climates this can lead to. soil erosion Without plant roots to anchor the soil, rain can easily wash the soil away. This soil ends up in waterways leading to the sedimentation of these areas.

42 HUMAN IMPACT ON THE CYCLE CLIMATE CHANGE is the change of previously stable global patterns of weather. This can affect the water cycle by affecting the amount of precipitation received around the world. Excessive precipitation Lack of precipitation creates. floods creates. droughts

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44 Created by Anh-Thi Tang Tangstar Science Copyright April 2013 Anh-Thi Tang (a.k.a. Tangstar Science) All rights reserved by author. This document is for personal classroom use only. This entire document, or any parts within, may not be electronically distributed or posted to any website.